using System;

public class Program

{

    public static void Main()

    {

            Console.WriteLine(" MENU PROGRAM RESPONSI : ");

            Console.WriteLine(" 1. Luas Bola ");

            Console.WriteLine(" 2. Faktorial Bilangan ");

            Console.WriteLine(" 3. Rata - Rata Data IPK ");

​

                Console.Write("\n\n Masukkan Nomor Case : ");

                int switchmilih;

                switchmilih = Convert.ToInt32(Console.ReadLine());

​

                switch (switchmilih)

                {

                    case 1:

                        Console.WriteLine("\n 1. Luas Bola ");

                        Console.Write(" Masukkan jari-jari bola : ");

                        double jarijari;

                        jarijari = Convert.ToInt32(Console.ReadLine());

                        double pi = 3.14;

                        double luasbola = 4 * pi * jarijari;

                        Console.WriteLine(luasbola);

                        break;

​

                    case 2:

                        break;

case 3:

                        Console.WriteLine("\n 3. Rata - Rata Data IPK ");

                        Console.Write(" Masukkan Jumlah Data : ");

                        int jumlahdata = Convert.ToInt32(Console.ReadLine());

                        int[] array = new int[jumlahdata];

                        int sum = 0;

                        double average = 0;

                        for (int a = 0; a < array.Length; a++)

                        {

                        while(!int.TryParse(Console.ReadLine(), out array[a]))

                        {

                        Console.WriteLine("Entered not a character");

                        }

                         sum += array[a];

                        average = sum/array.Length;

                         }

                         Console.WriteLine("Jumlah Data : " + sum);

                        Console.WriteLine("Rata-Rata Data : " + average);

                        break;

                }

            }

        }